Grid voltage level spanning operational strategies for battery energy storage systems in distribution grids

With rising renewable generation and battery storage prices decreasing, storage integration in electrical grids is increasingly discussed as an option to avoid conventional grid extension as well as an option for new business models for utilities and customers. While the majority of available literature focuses only on the low-voltage level, the impact that distributed storages can have on the superimposed medium-voltage grid has to be considered. Especially in grids with high distributed renewable generation, battery storages can contribute to a grid operation conforming to standards. In this paper an operational strategy is presented that includes medium-voltage/low-voltage transformers as well as the high-voltage/medium-voltage transformer into the control algorithm. Results obtained by simulations show, that battery storage systems in low-voltage grids can efficiently relieve the superimposed medium-voltage grid and the transformer connecting it to the high-voltage level.